Michael I. Bruce

Cluster Chemistry: XVII.Radical ion-initiated synthesis of ruthenium cluster carbonyls containing tertiary phosphines, phosphites, arsines, SbPh3, or isocyanides☆

The syntheses of over sixty known and new derivatives of Ru3(CO)12 and H4Ru4(CO)12 by substitution reactions initiated by sodium diphenylketyl are described. The range of ligands studied includes isocyanides, tertiary phosphines and phosphites, tertiary arsines and SbPh3. The reactions are characterised by high degrees of specificity and conversion: under mild conditions up to four ligands can be introduced. Comparisons with the corresponding thermally induced reactions are made in several cases. The reactions provide routes to mixed ligand derivatives of the cluster carbonyls, although account of relative Lewis base strengths of the ligands may have to be taken. Possible mechanisms of these reactions are discussed briefly, as are the IR ν (CO) spectra of the Ru3 (CO)12-nLn complexes.

Transition Metal Complexes Containing All-Carbon Ligands

Publisher Summary This chapter surveys the rapidly growing field comprising the chemistry of transition metal complexes containing ligands which are made up only of carbon atoms within their coordination spheres. The chapter describes metal complexes which contain linear or cyclic ligands of composition C n (n n ligands, in order of increasing carbon content of the ligand have been discussed. This is followed by a discussion on complexes of cyclic all-carbon ligands, such as [C 3 {Fe(CO) 2 Cp} 3 ] + . Complexes containing C n ligands associated with binuclear metal–metal bonded systems are followed by an account of metal cluster complexes containing C n ligands. It also includes hybrid complexes where a cluster supports a C n ligand also attached to a mononuclear metal–ligand fragment. The study is broadly based on a group-by-group approach and includes salient details of synthesis, properties, chemistry and electronic structure.

Vinylidene and Propadienylidene (Allenylidene) Metal Complexes

Publisher Summary The rapid development of the chemistry of transition-metal complexes containing terminal carbene (A) or carbyne (B) ligands has been followed more recently by much research centered on bridged methylene compounds (C). As often occurs in new and developing areas of chemistry, some confusion about the nomenclature of these complexes has arisen. Protonation or alkylation of several ethynyl–metal derivatives gives the corresponding vinylidene complexes in high yield. Several vinylidene complexes of the group VI metals have been obtained by heating σ–chlorovinyl derivatives with tertiary phosphines, phosphites, arsines, or stibines. Several complexes containing μ -C=CHR ligands have been obtained directly from 1-alkynes and two equivalents (or excess) of an appropriate precurso. A general route to complexes containing propadienylidene ligands is by loss of water or alcohols from suitable carbene or vinylidene precursors, or of oxo or alkoxy functions from ynolate anions. The majority of the chemistry of vinylidene and propadienylidene complexes is concerned with their synthesis and reactions. Vinylidene is one of the best π-acceptors known and is exceeded only by SO 2 and CS. The vinylidene ligand occupies an important place in the sequence of reactions linking a variety of well-known η 1 -carbon-bonded ligands. Metal cluster complexes containing vinylidene ligands have been considered as models of species present when olefins or alkynes are chemisorbed on metal surfaces.

Cluster chemistry: LVI. Stereochemistry of group 15 ligand-substituted derivatives of M3(CO)12 (M = Ru, Os) B. X-Ray structures of six complexes M3(CO)10(L)2 (M = Ru, L = PPh3, PPh(OMe)2, and P(OCH2CF3)3; M = Os, L = PPh3, PPh(OMe)2 and P(OMe)3)

Abstract X-Ray crystal structures of six complexes of the type M 3 (CO) 10 (L) 2 (M = Ru, L = PPh 3 , PPh(OMe) 2 , and P(OCH 2 CF 3 3 ; M = Os, L = PPh 3 , PPh(OMe) 2 and P(OMe) 3 ) have been determined. All contain a triangular M 3 core; the two phosphorus ligands occupy equatorial positions on adjacent metal atoms so that they are approximately trans to each other at the ends of the M-M vector. In contrast to complexes M 3 (CO) 11 (L), there is no prounounced lengthening of the MM bonds cis to the group 15 ligand. Other features, including twisting of the ML 4 groups to distort the D 3h symmetry towards D 3 , are similar to those found for monosubstituted complexes. Thermal reactions between Os 3 (CO) 12) and P(OMe) 3 , which afford Os 3 (CO) 12- n {P(OMe) 3 } n ( n = 1–4), are described. Crystal data: Ru 3 (CO) 10 (PPh 3 ) 2 : orthorhombic, P 2 1 2 1 2 1 , τa 34.636(15), b 17.007(10)(10), c 14.806(4) A, U 8721(7) A 3 , Z = 8, N 0 (number of ‘observed’ data with I > 3σ( I ) = 4773, R = 0.071, R ′ = 0.080; Os 3 (CO) 10 (PPh 3 2 : monoclinic, P 2 1 / n , a 17.104(6), b 34.507(11), c 14.832(6) A, β 92.28(3)°, U 8747(5) A 3 Z = 8, N 0 = 8011, R = 0.048, R ′ = 0.040; Ru 3 (CO) 10 {PPh(OMe) 2 } 2 : monoclinic, Pc, a 9.014(4), b 8.545(4), c 21.728(5) A, β 100.77(3)°, U 1644(1) A 3 , Z = 2, N 0 = 5269, R = 0.024, R ′ = 0.027; Os 3 (CO) 10 {PPh(OMe) 2 } 2 : monoclinic, Pc, a 9.007(5), b 8.565(7), c 21.716(12) A, β 100.87(5)°, U 1645(1) A 3 , Z = 2, N 0 = 5266, R = 0.041, R ′ = 0.043; Ru 3 (CO) 10 {P(OCH 2 CF 3 ) 3 } 2 : orthorhombic, P 2 1 2 1 2 1 , a 29.79(2), b 15.827(8), c 8.283(4) A, U 3906(3) A 3 , Z = 4, N 0 = 2652, R = 0.063, R ′ = 0.070; Os 3 (CO) 10 {P(OMe) 3 } 2 : triclinic, P 1 , a 24.955(10), b 9.439(4), c 8.944(4), A, a 84.02(3), β (3), γ 84.18(3)°, U 2083(1) A 3 , Z = 3, N 0 = 40.84, R = 0.057, R ′ = 0.068.

Cluster chemistry. LVII: Stereochemistry of group 15 ligand-substituted derivatives of M3(CO)12 (M=Ru, Os). C. X-ray structures of Ru3(CO)9(L)3 (L=PMe2(CH2Ph), PMe2Ph, AsMe2Ph, PPh(OMe)2, P(OEt)3, and P(OCH2CF3)3) and Os3(CO)9(PPh3)3

The molecular structures of Ru3(CO)9(L)3 (L = PMe2(CH2Ph), PMe2Ph, AsMe2Ph, PPh(OMe)2, P(OEt)3 and P(OCH2CF3)3) and Os3(CO)9(PPh3)3 have been determined by single-crystal X-ray diffraction methods. The tertiary phosphine, arsine or phosphite ligands occupy equatorial sites, one per metal atom, so arranged that each is as far from the other two as possible. The unit cell of the PPh(OMe)2 complex is unusual in containing four conformationally distinct molecules, two of which contain disordered Ru3 cores. Metalmetal and metalligand separations are similar to those found in Me3(CO)12 and mono- or disubstituted complexes, respectively. Considerable distortion towards D3 symmetry is found, with MMCO angles approaching those calculated for semi-bridging CO groups in the case of the P(OEt)3 complex. Crystal data: Ru3(CO)9(PMe2Ph)3, orthorhombic, P212121, a 21.343(2), b 14.752(4), c 12.170(2) A, U 3832(1) A3, Z = 4, N0 (number of ‘observed’ data with I > 3σ(I)) = 3601, R = 0.040, R′ = 0.048; Ru3(CO)9-(AsMe2Ph)3, triclinic, P1, a 19.113(4), b 15.375(4), c 13.756(3) A, α 89.36(2), β 85.97(2), γ 77.61(2) °, U 3939(2) A3, Z = 4, N0 = 8823, R = 0.046, R′ = 0.047; Ru3(CO)9{PMe2(CH2Ph)}3, trigonal, P3, a 12.766(10), c 15.583(9) A, U 2202(2) A3, Z = 2, N0 = 1966; R = 0.093, R′ = 0.117; Ru3(CO)9{PPh(OMe)2}3, triclinic, P1, a 23.23(1), b 20.87(1), c 20.73(1) A, α 98.21(4), β 111.07(3), γ 111.95(4) °, U 8237(7) A3, Z = 8, N0 = 16532, R = 0.041, R′ = 0.039; Ru3(CO)9{P(OEt)3}3, triclinic, P1, a 18.170(6), b 13.016(6), c 10.035(3) A, α 68.83(3), β 80.42(3), γ 78.10(4) °, U 2154(1) A3, Z = 2, N0 = 4318, R = 0.051, R′ = 0.061; Ru3(CO)9{P(OCH2CF3)3}3, triclinic, P1, a 21.036(2), b 13.146(1), c 9.376(2) A, α 82.68(1), β 88.40(1), γ 85.59(1) °, U 2564(1) A3, Z = 2, N0 = 3966, R = 0.066, R′ = 0.068; Os3(CO)9(PPh3)3, triclinic, P1, a 18.207(5), b 17.911(6), c 12.928(3) A, α 94.13(2), β 98.98(2), γ 110.56(2) °, U 3862(2) A3, Z = 2, N0 = 3216, R = 0.092, R′ = 0.084.

Cluster chemistry : X. Preparation of 1,2-bis(diphenylphosphino)ethane derivatives of Ru3(CO)12: crystal and molecular structures of Ru3(CO)10(η-PH2PCH2CH2PPh2)

The reactions of dppe with Ru3(CO)12 catalysed by Ph2CO??? have been investigated. Under the appropriate conditions Ru3(CO)11(PPh2CH2CH2PPh2) (with only one P atom coordinated), [Ru3(CO)11]2(η-dppe) (with one dppe ligand bridging two Ru3(CO)11 clusters), Ru3(CO)10(η-dppe) and Ru3(CO)8(η-dppe)2(both with dppe bridging Ru-Ru bonds) can all be isolated in good yields. A full X-ray crystallographic analysis of Ru3(CO)10(η-dppe) shows that it crystallizes in the triclinic system, space group P, a 10.615(2), b 11.769(6), c 16.584(4) A, α 75.68(2), β 84.59(2), γ 69.64(2)°. The structure was refined to R = 0.030, Rw = 0.034 using 3558 data with I ⩾ 2.5 σI. The dppe ligand bridges a Ru-Ru bond (2.856(1) A), occupying equatorial sites on adjacent Ru atoms. Other distances: non-bridged RuRu bonds are 2.855(1), 2.847(1); RuP, 2.330(2) A.

Some complexes of all-carbon ligands and related chemistry

Abstract Recent developments in the chemistry of all-carbon ligands and related molecules include the synthesis and reactions of mono-, bi- and poly-nuclear complexes containing C2, C4 and C8 ligands, as well as of substituted derivatives of allenylidene (:C=C=CH2) and butatrienylidene (:C=C=C=CH2) ligands. The work of the Adelaide group on the pentanuclear ruthenium cluster carbonyl containing a reactive C2 ligand and on the synthesis, chemistry and electrochemistry of a variety of complexes containing C4 and C8 ligands, is described.

Cyclopentadienyl-ruthenium and -osmium chemistry. Cleavage of tetracyanoethylene under mild conditions: X-ray crystal structures of [Ru{η3-C(CN)2CPhCC(CN)2}(PPh3)(η-C5H5)] and [Ru{C[C(CN)2]CPhC(CN)2}-(CNBut)(PPh3)(η-C5H5)]

The reaction between [RU(C2Ph)(PPh3)2(η-C5H5)] and C2(CN)4 affords [Ru{η3-C(CN)2 CPhCC(CN)2}-(PPh3)(η-C5H5)](2), which forms [Ru{C[C(CN)2]- CPhC(CN)2}(L)(PPh3)(η-C5H5)](5) with L = CO or CNBut; the structures of (2) and (5; L = CNBut) have been determined by X-Ray crystallography.

Cluster chemistry: XXXXVIII. Some reactions of Ru3(CO)12 with nitrogen heterocycles. X-ray crystal structures of Ru3(μ-CO)2(CO)8(bipy) and Ru3(μ-H){μ-N2C3H(CF3)2-3,5}(CO)10

Abstract Reactions between Ru 3 (CO) 12 and the nitrogen heterocycles pyridine, 2,2′-bi-pyridyl, pyrazole, 3,5-dimethylpyrazole and 3,5-bis(trifluoromethyl)pyrazole are described. Pyridine afforded the cyclometallated complex Ru 3 (μ-H)(μ-NC 5 H 4 )(CO) 10 , which with excess pyridine formed Ru 3 (μ-H) 2 (μ-NC 5 H 4 ) 2 (CO) 8 . 2,2′-Bipyridyl gave purple Ru 3 (μ-CO) 2 (CO) 8 (bipy), shown by an X-ray structure to have an Fe 3 (CO) 12 -type structure, with the bipy chelating one of the CO-bridged Ru atoms. The pyrazoles gave Ru 3 (μ-H)(μ-N 2 CP 3 HR 2 )(CO) 10 (R = H, Me or CF 3 ), in which the pyrazolide ligand spans an RuRu bond also bridged by H, as shown by the X-ray structure of the CF 3 derivative. The bipyridyl and pyrazole complexes both crystallise in the monoclinic system, the former in space group P 2 1 / n with unit cell dimensions a 7.834(2), b 25.818(2), c 11.717(1) A, β 107.41(1)° with Z = 4 and the latter in space group P 2 1 / c , unit cell dimensions a 16.802(3), b 7.726(1), c 18.807(3) A, β 114.24(1)° with Z = 4. The structures were refined by conventional least-squares methods with the use of 3336 (2993 for the pyrazole structure) reflections with I > 2.5σ( I ) to final R = 0.031 and R w = 0.034 (0.025 and 0.026).

Cyclopentadienyl-ruthenium and -osmium chemistry: XXVII. X-ray structures of Ru(CCPh)(dppe)(η-C5H5) and of [Ru(L)(PPh3)2(η-C5H5)]X (L = C(OMe)Et, X = PF6; L = CCMePh, X = I)☆

Determinations of the crystal structures of the acetylide Ru(CCPh)(dppe)(η-C5H5), the vinylidene [Ru(CCMePh)(PPh3)2(η-C5H5)]I and the carbene [Ru{C(OMe)Et}(PPh3)2(η-C5H5)][PF6], have enabled comparison of the RuC(α) bonds in these and a number of related complexes. Cationic complexes have RuC bonds shorter (by 0.05–0.1 A) than values expected on the basis of normal covalent radii, but in the case of vinyl and acetylide complexes there does not appear to be any significant shortening of the RuC bond which can be ascribed to back-bonding from the metal to the unsaturated carbon-bonded ligand. Ru(CCPh)(dppe)(η-C5H5) crystallises in the monoclinic space group P21/n, with a 14.642(4), b 14.018(3), c 16.490(4) A, β 105.08(2)°, Z 4; [Ru(CCMePh)(PPh3)2(η-C5H5)]I crystallises in the orthorhombic space group P212121, a 12.612(4), b 15.607(3), c 22.357(6) A, Z 4; [Ru{C(OMe)Et}(PPh3)2(η-C5H5)][PF6 crystallises in the orthorhombic space group P212121, a 11.999(3), b 14.948(1), c 22.342(3) A, Z 4. For 4841, 2614 and 3299 data (I > 2.5σ(I), respectively, refinements converged with R, Rw values of 0.038 and 0.048, 0.047 and 0.053, and 0.040 and 0.044 for the three complexes.